Hello
I'm using "Extension Builder" but I'm having difficulty:
In "HTML Render" can not reference a css? Ex.:
<link href = "/ mystyle.css">

I added as an attachment the file "mystyle.css" because it is large, it works perfectly when viewing in the browser, but when I will see it in my project it goes unformatted.

Another thing, why should I insert the code in "Html Render" for a "Live HTML rendering" instead of the Extension Builder automatically generate the "Preview"? Because in my case, I'm making a menu, and the same code that goes on each tab separately (Between ... Aflter ...) I'll have to put in the "Render Html". Would not it be easier in "Preview" to see the code for all tabs (at runtime) and not "Render Html"?